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تسجيل مستخدم جديدSoft and Diffractive Phenomena
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تأليف
R. Eichler
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Recent results on hard diffraction at HERA and the Tevatron are presented. Charged particle multiplicities in diffraction and differences in multiplicity in quark and gluon jets measured at LEP are discussed. Spin effects in the fragmentation of leading quarks show some interesting features.
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Preliminary results from the D0 experiment on jet production with rapidity gaps in $pbar{p}$ collisions are presented. A class of dijet events with a forward rapidity gap is observed at center-of-mass energies $sqrt{s}$ = 1800 GeV and 630 GeV. The nu
mber of events with rapidity gaps at both center-of-mass energies is significantly greater than the expectation from multiplicity fluctuations and is consistent with a hard single diffractive process. A class of events with two forward gaps and central dijets are also observed at 1800 GeV. This topology is consistent with hard double pomeron exchange. We also present proposed plans for extending these analysis into Run II through the use of a forward proton detector.
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Jet and charm quark production in diffractive interactions is sensitive to the partonic structure of the diffractive exchange. This article reviews recent cross section measurements of such processes in both deep-inelastic scattering (DIS) regime and
photoproduction (PHP) from the HERA ep collider experiments. The cross sections are compared to next-to-leading order QCD calculations based on factorisation theorem.
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